The present invention is directed to a dental applicator for applying amalgam or other filling material to teeth. More particularly, the present invention is directed to a dental applicator which can be repeatedly used without any danger of permanent clogging by hardened amalgam or filling material and which, in a preferred embodiment, comprises an amalgam dispenser which can be removed from a handle, e.g., for cleaning, replacement or alternative size combinations.
Various types of lever-activated dental amalgam applicators are known, as exemplified by U.S. Pat. No. 5,580,245 to Nevin, U.S. Pat. No. 4,355,976 to Bemer, U.S. Pat. No. 4,273,534 to Seid, U.S. Pat. No. 4,306,864 to Law et al., U.S. Pat. No. 4,673,353 to Nevin and U.S. Pat. No. 3,735,492 to Karter et al. For example, U.S. Pat. No. 4,673,3 53 to Nevin discloses a lever-operated applicator 10 for a light-curable dental composition in which a hollow receptacle 50 is coupled to the lever 30 and elevated by depressing the lever arm 34 (column 3, lines 47-54). The receptacle is formed from inert metal or opaque plastic (column 3, lines 58-59) while the plunger 18 which extends through the receptacle cavity can be made of any conventional clear plastic such as methacrylic acid and polymer, methylmethacrylate polymer, polycarbonate or polystyrene (column 3, lines 64-67). Preferably, a clear solid plastic core 60 forming plunger 18 is surrounded by an inert metal or plastic coating (column 3, lines 67-column 4, line 17). U.S. Pat. No. 4,273,534 to Seid discloses an amalgam carrier and dispenser having a terminal end surface 16 of a plunger 10 formed of especially hard metallic material to resist abrasion effect.
Solidificator and clogging of amalgam in the receptacle or barrel of such lever-actuated dental amalgam applicators has been a significant problem encountered by dentists. Generally, amalgam is applied onto a tooth while at room temperature, e.g., about 68.degree. F. to about 70.degree. F., i.e., while in malleable condition. However, because amalgam is administered under ambient temperature of about 75-80.degree. F. (or even cooler if a dental office is air conditioned), amalgam begins to solidify immediately upon receipt within the lever-actuated barrel. Therefore, after repeated application, solidified amalgam builds upon interior surfaces of the cylindrical barrel, interfering with proper administration of amalgam filling into a tooth. Eventually, the entire barrel becomes totally clogged with solidified amalgam so that the entire amalgam applicator is rendered useless and must be discarded, handle and all.
Attempts have been made to create amalgam applicators with removable tips, e.g., U.S. Pat. No. 3,735,492 to Karter et al., so that once a tip becomes clogged, it can be removed from the amalgam carrier and replaced by a clean tip. However, such previous designs have proven cumbersome if not totally difficult to implement and furthermore do not solve the problem of initially preventing amalgam from adhering inside the lever-activated barrel.
Accordingly, it is an object of the present invention to improve dispensing and dispersing of dental amalgam or other filling material onto a tooth.
It is a more specific object of the present invention to inhibit or totally prevent accumulation of hardened amalgam or filling material within a lever-activated barrel of a dental amalgam carrier upon repeated actuation.
It is a further object of the present invention to provide a dental amalgam or filling applicator which can be effectively cleaned and re-used and/or having individual parts thereof which can be cleaned and re-used, such as a separable amalgam carrier and handle.
Further objects of the present invention will become apparent from the description herein.